Heathkit H9 Manual page 16

Page 14
TTL Connections
]- l
77
rc 60r
-------_lr
t
1 2 0
:"*-H
@
rc 6t2
r/0 ctRcutT
B OA R D
PICIORIAL 2.7
TTL Serial Input/Output
Pictorial 2-7 shows the iumper wires necessary for the
TTL configuration. The TTL inputs are standard TTL
logic levels as shown in Pictorial 2-8. A mark is de-
fined as a logic 1 and a space is defined as a logic 0.
TT L IN P U ]
LE V EL S
+ 5
t) A
+ .4
0
T TL O U TP U T
LE V TL S
PICTORIAL 2.8
Pictorial 2-9 shows the partial schematic of the TTL
wiring on the I/O circuit board. The jumper wire that
disables the reader control is shown in pictorials 2-7
and 2-9. Refer to "Reader Control" on Page 18.
E-(\c
oeoirs I
iL Vi
- icers I
M AR K ( LO GI C 1 )
S P A C E (L OG I C O)
M A RK ( LO G IC I )
P A C I {L OG I C ( ) )